In language analysis a level of detachment is required, by saying that writer's approach was actually 'measured' rather than saying that the approach was intended to be 'measured', you step over the line between language analysis and endorsing/critiquing arguments. It would be better to say: "By adopting this approach, the author seeks to convince readers that their argument is measured and reasonable, and that they have considered the issue thoughtfully from both sides, and are not attacking the proposal just for the sake of it."
Same with: "The alarmist approach of comparing the government?s daily compulsory exercise proposal to the actions of China?s Mao regime strives to convince the audience that the suggestion is extreme, and unnecessarily getting involved in issues which are up to the individual to address. "
I would re-write that as: "By comparing the government?s daily compulsory exercise proposal to the actions of China?s Mao regime the writer strives to alarm the audience and to convince them that the proposal is extreme, unnecessarily impinging on individual liberties"
"A ?we know best? tone"
You could also describe that as a 'tone of authority', or an 'authoritative tone'.
"to plant doubt"
if you want to use the full expression then say it, if not then just say "to place doubt in the minds of ....".